c61f216d37
- We just add to a frame of quads which the renderer deals with in gfx_update - draw_quad, draw_rect, draw_rect_rotated - Currently just implemented with legacy opengl, so we can't do custom shading - Added third party code from lodepng so we can load pngs without any other dependencies (no C includes) - ALLOCATOR_REALLOCATE - Basic Vector2, Vector3, Vector4 stuff, and some math utilities - Added <math.h> dependency for now. - Graphics renderer frontend layer - Naive get_random() implementation
115 lines
No EOL
3.3 KiB
C
115 lines
No EOL
3.3 KiB
C
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/*
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Usage:
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Just call draw_xxx procedures anywhere in the frame when you want something to be drawn that frame.
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// Examples:
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// Verbose
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Draw_Quad quad;
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quad.bottom_left = v2(x, y);
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quad.top_left = v2(x, y);
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quad.top_right = v2(x, y);
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quad.bottom_right = v2(x, y);
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quad.color = v4(r, g, b, a);
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draw_quad(quad);
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// Basic rect. Bottom left at X=-0.25, Y=-0.5 with a size of W=0.5, H=0.5
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draw_rect(v2(-0.25, -0.5), v2(0.5, 0.5), COLOR_GREEN);
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// Rotated rect. Bottom left at X=-0.25, Y=-0.5 with a size of W=0.5, H=0.5
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// With a centered pivot (half size) and a rotation of 2.4 radians
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// If pivot is v2(0, 0), the rectangle will rotate around it's bottom left.
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draw_rect_rotated(v2(-0.25, -0.5), v2(0.5, 0.5), COLOR_GREEN, v2(0.25, 0.25), 2.4f);
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*/
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#define QUADS_PER_BLOCK 1024
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typedef struct Draw_Quad {
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Vector2 bottom_left, top_left, top_right, bottom_right;
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// r, g, b, a
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Vector4 color;
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} Draw_Quad;
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typedef struct Draw_Quad_Block {
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Draw_Quad quad_buffer[QUADS_PER_BLOCK];
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u64 num_quads;
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struct Draw_Quad_Block *next;
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} Draw_Quad_Block;
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typedef struct Draw_Frame {
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Draw_Quad_Block first_block;
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Draw_Quad_Block *current;
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} Draw_Frame;
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// This frame is passed to the platform layer and rendered in os_update.
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// Resets every frame.
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Draw_Frame draw_frame = ZERO(Draw_Frame);
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void draw_quad(Draw_Quad quad) {
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if (!draw_frame.current) draw_frame.current = &draw_frame.first_block;
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assert(draw_frame.current->num_quads <= QUADS_PER_BLOCK);
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if (draw_frame.current->num_quads == QUADS_PER_BLOCK) {
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draw_frame.current->next = cast(Draw_Quad_Block*)talloc(sizeof(Draw_Quad_Block));
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draw_frame.current = draw_frame.current->next;
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draw_frame.current->next = 0;
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draw_frame.current->num_quads = 0;
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}
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draw_frame.current->quad_buffer[draw_frame.current->num_quads] = quad;
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draw_frame.current->num_quads += 1;
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}
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void draw_rect(Vector2 position, Vector2 size, Vector4 color) {
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const float32 left = position.x;
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const float32 right = position.x + size.x;
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const float32 bottom = position.y;
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const float32 top = position.y+size.y;
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Draw_Quad q;
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q.bottom_left = v2(left, bottom);
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q.top_left = v2(left, top);
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q.top_right = v2(right, top);
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q.bottom_right = v2(right, bottom);
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q.color = color;
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draw_quad(q);
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}
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void draw_rect_rotated(Vector2 position, Vector2 size, Vector4 color, Vector2 local_pivot, float32 rotation) {
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const float32 left = position.x;
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const float32 right = position.x + size.x;
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const float32 bottom = position.y;
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const float32 top = position.y+size.y;
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Vector2 bottom_left = v2(left, bottom);
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Vector2 top_left = v2(left, top);
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Vector2 top_right = v2(right, top);
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Vector2 bottom_right = v2(right, bottom);
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Vector2 pivot = v2(position.x + local_pivot.x, position.y + local_pivot.y);
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Draw_Quad q;
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q.bottom_left = v2_rotate_point_around_pivot(bottom_left, pivot, rotation);
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q.top_left = v2_rotate_point_around_pivot(top_left, pivot, rotation);
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q.top_right = v2_rotate_point_around_pivot(top_right, pivot, rotation);
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q.bottom_right = v2_rotate_point_around_pivot(bottom_right, pivot, rotation);
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q.color = color;
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draw_quad(q);
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}
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#define COLOR_RED ((Vector4){1.0, 0.0, 0.0, 1.0})
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#define COLOR_GREEN ((Vector4){0.0, 1.0, 0.0, 1.0})
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#define COLOR_BLUE ((Vector4){0.0, 0.0, 1.0, 1.0}) |