Legacy GM Applying One Texture Across Multiple Faces?

[Bowbowis]

Hello, I've been using GM for several years now but this is my first time posting on the forum so forgive me if I make any mistakes here.

My problem is thus, I'm creating a game in which I have a number of textures, like this:

​

I need to resize one side of these textures so that it appears to be further than the other, like this:

​

I've been able to recreate the effect by using textured line primitives for each column of pixels, but it chews up a ton of RAM and only works for resizing the left or right side. To combat this problem I've been trying to use a square made from a triangle strip like this:

draw_primitive_begin_texture (pr_trianglestrip, bgtex);

draw_vertex_texture_colour (px0 + 000, py0 + 160, uvs [0] / (texmapw * 1), uvs [3] / (texmaph * 1), -1, alpha);
draw_vertex_texture_colour (px0 + 000, py0 + 000, uvs [0] / (texmapw * 1), uvs [1] / (texmaph * 1), -1, alpha);
draw_vertex_texture_colour (px0 + 160, py0 + 160, uvs [2] / (texmapw * 1), uvs [3] / (texmaph * 1), -1, alpha);
draw_vertex_texture_colour (px0 + 160, py0 + 000, uvs [2] / (texmapw * 1), uvs [1] / (texmaph * 1), -1, alpha);

draw_primitive_end ();

​

The problem comes when I try to shrink one of the sides. When I reduce the distance between points this is the result:

​

As you can see the shape is correct. The problem is that each face is textured separately. Adjusting the proportions of one triangle does not affect the texture on other triangles. That brings me to my question: Is there any way to apply a single texture to both triangles so that the texture on one will be adjusted based on the vertices of the other?

 

[Insanebrio]

An easy solution is to add more points horizontally in the center to make a better image. I cant post an image now, but now you have

B D
A C

instead you should have

B D F H..
A C E G..

 

[Dennis Ross Tudor Jr]

it looks like you have your draw vertices in the wrong order possibly. When I look at your last image, what I see on the right side is the wood panel coming towards me. But when I look at the left side of the image, it looks as if the wood panel is going away from me. This could be caused by either misording of the the draw vertices or by mis-ordering the text vertices. I am thinking the former because of the upper and right side of the image. Instead of ording them B, A, D, C try ordering the verices A, C, B, D instead

 

[Bowbowis]

Thanks for your suggestions guys. Unfortunately neither of them were able to solve my problem.

To reiterate I'm looking for a way to apply the texture so that the strip is treated as a single square rather than as a pair of triangles.

 

[Harrison Vanderbyl]

-use the inbuilt 3d functionality of gamemaker d3d_draw_vertex and the like

 

[Nux]

Spoiler: BIN

Correct me if i'm wrong, but when I worked with primitives, I was certain they went in a backwards-Z action, not an N action.

C-----D            _.D
 \              _.-
  \            C
   \    -->     \
    \          A._\
     \            -.\
A-----B             -B
               (omg this is so bad)

Edit: Ho boy, I didn't even know what affine texture mapping was, sorry! Follow Lonewolff's advice.